722 research outputs found
Vivian-Felde/Diatom_diversity_Vydrino_Lake_Baikal: Public release
No full textTitle
Long-term trends in diatom diversity and palaeoproductivity: a 16 000-year multidecadal study from Lake Baikal, southern Siberia.
Authors
Anson W. Mackay, Vivian A. Felde, David W. Morley, Natalia Piotrowska, Patrick Rioual, Alistair W. R. Seddon, and George E. A. Swann
Corresponding author
Anson W. Mackay ([email protected])
Description
This repo contains R code and data to calculate diatom diversity and investigate the diversity – palaeoproductivity relationship on the Vydrino shoulder of Lake Baikal during the Late Glacial and Holocene.
The diatom and metadata can be downloaded from NOAA https://doi.org/10.25921/q6v1-5q02.
See
Anson W. Mackay, Vivian A. Felde, David W. Morley, Natalia Piotrowska, Patrick Rioual, Alistair W. R. Seddon, and George E. A. Swann 2022. Long-term trends in diatom diversity and palaeoproductivity: a 16 000-year multidecadal study from Lake Baikal, southern Siberia. Clim. Past, 18, 1-18, https://doi.org/10.5194/cp-2020-70.
Abstract
Biological diversity is inextricably linked to community stability and ecosystem functioning, but our understanding of these relationships in freshwater ecosystems is largely based on short-term observational, experimental, and modelling approaches. Using a multidecadal diatom record for the past ca. 16 000 years from Lake Baikal, we investigate how diversity and palaeoproductivity have responded to climate change during periods of both rapid climate fluctuation and relative climate stability. We show dynamic changes in diatom communities during the past 16 000 years, with decadal shifts in species dominance punctuating millennial-scale seasonal trends. We describe for the first time in Lake Baikal a gradual shift from spring to autumnal diatom communities that started during the Younger Dryas and peaked during the Late Holocene, which likely represents orbitally driven ecosystem responses to long-term changes in seasonality. Using a multivariate classification tree, we show that trends in planktonic and tychoplanktonic diatoms broadly reflect both long-term climatic changes associated with the demise of Northern Hemisphere ice sheets and abrupt climatic changes associated with, for example, the Younger Dryas stadial. Indeed, diatom communities are most different before and after the boundary between the Early and Middle Holocene periods of ca. 8.2 cal kyr BP, associated with the presence and demise of Northern Hemisphere ice sheets respectively. Diatom richness and diversity, estimated using Hill's species numbers, are also shown to be very responsive to periods characterized by abrupt climate change, and using knowledge of diatom autecologies in Lake Baikal, diversity trends are interpreted in 30
terms of resource availability. Using diatom biovolume accumulation rates (BVARs; μm^3 cm^-2 yr^-1), we show that spring diatom crops dominate palaeoproductivity for nearly all of our record, apart from a short period during the Late Holocene, when autumnal productivity dominated between 1.8–1.4 cal kyr BP. Palaeoproductivity was especially unstable during the Younger Dryas, reaching peak rates of 18.3 x 10^3 μm^3 cm^-2 yr^-1 at ca. 12.3 cal kyr BP. Generalized additive models (GAMs), which explore productivity–diversity relationships (PDRs) during pre-defined climate periods, reveal complex relationships. The strongest statistical evidence for GAMs were found during the Younger Dryas, the Early Holocene, and the Late Holocene, i.e. periods of rapid climate change. We account for these differences in terms of climate-mediated resource availability, and the ability of endemic diatom species in Lake Baikal to adapt to extreme forms of living in this unique ecosystem. Our analyses offer insight into how productivity–diversity relationships may develop in the future under a warming climate
Vivian Henderson Papers
No full textDr. Vivian Wilson Henderson was the 18th president of Clark College from 1965 until his death in 1976. A native of Bristol, Tennessee, Henderson completed a Bachelor of Science degree in Economics from North Carolina College in Durham in 1947. He earned his Master of Arts and Doctor of Philosophy degrees in Economics from the University of Iowa in 1949 and 1952, respectively. The Vivian Wilson Henderson Papers document Dr. Henderson's personal and professional activities spanning the years 1940 to 1976. The photographs in the collection date primarily from the 1960s and document Henderson's activities at Clark College as well as his family life. Photographs of Dr. Henderson's wife, Anna, and children are included.
At the AUC Robert W. Woodruff Library we are always striving to improve our digital collections. We welcome additional information about people, places, or events depicted in any of the works in this collection. To submit information, please contact us at [email protected].
El Tlacuache Núm. 485 (2011). 485 Año 11 (2011) septiembre. El Tlacuache
No full textPresentación por Eduardo Corona Martínez. -El evolucionismo y la arqueología. Encuentros y desencuentros por Vivian Scheinsohn
Vivian Castleberry
No full textVivian Castleberry, a native Texas, was a graduate of Southern Methodist University (SMU) and became the first female editor of the Dallas Times Herald in 1957. During her 28-year tenure at the Herald, Ms. Castleberry won numerous journalism awards. She took an early retirement to pursue peace activist efforts. She co-founded the Women's Center of Dallas and The Dallas Women's Foundation, and founded Peacemakers Incorporated. She was inducted into the Texas Women's Hall of Fame in 1984. The photographer, Dian Malouf is a professional photographer, author, and internationally known jewelry designer. She is a native Texan and attended Southern Methodist University
Anna and Kimberly Henderson, 1968
No full textView of Anna Henderson, wife of Dr. Vivian Wilson Henderson, with daughter Kimberly Anne Henderson
A multidimensional ecological momentary assessment analysis of relations among negative affect, craving, and smoking cesation failure
No full textCessation failure occurs when smokers lapse within 24 hours of initiating a quit attempt. Although avoiding cessation failure is the first milestone of successful smoking cessation, little is known about the risk factors that influence cessation failure. This study examined whether or not multiple dimensions of real-time ratings of pre-quit negative affect and craving differentiated cessation failures from quit day abstainers. We hypothesized that cessation failures would experience greater severity, accelerated growth, and higher volatility in negative affect and craving in the two weeks preceding the target quit day than would successful abstainers. Results indicated that cessation failures and quit day abstainers did not differ in pre-quit dimensions of negative affect and craving. Those who failed to quit, however, experienced a greater reduction in craving after smoking during the 24 hours and four days before the target quit day than did successful quitters. The contingency between smoking and craving relief may indicate cessation failure risk in a way that pre-quit negative affect and craving trajectories and volatility do not.M.S.Includes bibliographical referencesby Vivian M Ye
Clark College Centennial Program, 1969
No full textThis audio recording consists of Clark Colleges centennial ceremony exercises. The main speaker for this ceremony is Dr. Lawrence Dunbar Reddick, a historian and the author of Dr. Martin Luther King, Jr.s biography. Dr. Reddick speaks to the audience about the importance of Clarks centennial for the history of black colleges. He stresses the important role the students play in maintaining the legacy of these schools and their futures. Dr. Vivian W. Henderson, 18th president of Clark College, then speaks on the forces that play a role in the shaky state of American higher education
Disseminating Cochrane evidence to the public health workforce via author-led webinars
No full text<b>Title</b>\ud
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- Disseminating Cochrane evidence to the public health workforce via author-led webinars\ud
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<b>Background</b> \ud
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- <u><a href="http://www.healthevidence.org/">Health Evidence™</a></u> is a free searchable repository, of 4,500+ quality-appraised public health relevant reviews, including nearly 700 Cochrane reviews. Author-led webinars is one knowledge translation strategy to disseminate the findings of Cochrane reviews.\ud
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<b>Objectives</b>\ud
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- (i) Disseminate the findings of Cochrane reviews via webinars\ud
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- (ii) Evaluate the impact of Cochrane author-led webinars \ud
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<b>Methods</b>\ud
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- Webinars are 60-90 minutes in length and include: an overview of the principles of evidence-informed decision making (15mins), a presentation of the findings by the review author (30mins), and a Q&A period (30mins). Webconferencing software monitors participant registration, attendance, engagement, poll responses, and questions. Standard polling questions are asked throughout each session to assess familiarity with and use of systematic reviews, as well as familiarity and agreement with session-specific review findings.\ud
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<b>Results</b>\ud
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- Since January 2015 Health Evidence™ has hosted six Cochrane author-led webinars. Webinar participants include: nurses, health promoters, physicians, dietitians, and knowledge brokers. On average, participants in each session were attentive and engaged 68.8% of the time. Google Analytics reflect an average 572% increase in users accessing the Cochrane review featured in each webinar on the day of the session compared to average daily access the month prior. On average, each session attracted 177 registrants, of which approximately half joined on the session date. Poll response data reveal 59.6% attendees use systematic reviews to inform their practice. Data collected pre/post on participant’s knowledge of the effectiveness of an intervention, suggest that webinars are an effective way to influence participant’s knowledge about intervention effectiveness (participant knowledge improved 10-31.8%, measured via pre/post poll questions). During the Q&A period, attendees submitted 5-12 questions per session.\ud
Conclusion: Webinars are an interactive and effective mechanism for promoting public health relevant Cochrane evidence to decision makers. Data from webinars highlight a high level of interest and engagement with Cochrane author-led sessions
Claudii Galeni opera omnia Book 1
No full textSeries: Medicorum graecorum opera quae exstant, v. 1-20Vol. 20 contains F. W. Assmann's Index in Galeni libros (Issued with Nutton, Vivian. Karl Gottlob Kühn and his edition of the works of Galen. Oxford, 1976.
Claudii Galeni opera omnia Book Index
No full textSeries: Medicorum graecorum opera quae exstant, v. 1-20Vol. 20 contains F. W. Assmann's Index in Galeni libros (Issued with Nutton, Vivian. Karl Gottlob Kühn and his edition of the works of Galen. Oxford, 1976.
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